Yeast Research Paper

YEAST Yeasts are eukaryotic unicellular fungi which reproduce by budding or fission. Yeasts are very small, typically 5 to 10 microns (1 micron = 10-4 centimeters) which is around 5 times the size of most bacteria. Yeast cell membranes acts as impermeable barriers against hydrophilic molecules to prevent the mixing of the cytoplasm and external environment. Around 7.5 n thick, the cell membrane is composed of a lipid bilayer (Walker, 1998). As with all eukaryotic membranes, the lipid bilayer contains globular proteins dispersed throughout a lipid membrane, to form a fluid mosaic structure (Nicholson & Singer, 1972).

Saccharomyces cerevisiae Saccharomyces cerevisiae, commonly known as Baker's yeast; a species of yeast is a unicellular fungus that reproduces by budding. The whole Saccharomyces cerevisiae nuclear genome contains 16 chromosomes including more than 13 million bases. As all other eukaryotic organisms the yeast Saccharomyces cerevisiae contains an additional, extra nuclear genome in the mitochondria. The cell wall consists of three components: glucan, mannoproteins and chitin.

It is believed that Saccharomyces cerevisiae was originally isolated from the skin of

These organisms have long been utilized to ferment the sugars of rice, wheat, barley, and corn to produce alcoholic beverages and in the baking industry to expand, or raise dough. Saccharomyces cerevisiae is commonly used as baker's yeast and for some types of fermentation. The yeast's function in baking is to ferment sugars present in the flour or added to the dough. This fermentation gives off carbon dioxide and ethanol. The carbon dioxide is trapped within tiny bubbles and results in the dough expanding, or rising. Yeast is often taken as a vitamin supplement because it is 50 percent protein and is a rich source of B vitamins, niacin, and folic